NEAR 101 Dacade unit test contract

Table of Contents

• Introduction
• Project setup
• Write a couple of tests for the contract
• TLDR

Introduction

After finish course 101 NEAR from dacade. I realized that the course has not yet implemented unit testing for smart contracts. In blockchain, writing unit tests is very important to increase security before publishing the contract on the mainnet.

The course using assembly script for smart contract, i plan to implement unit test by using as-pect and the syntax resembles RSpec. The library is well documented but sometimes the tests for the testing library might be the best source of examples to help you learn quickly.

Project setup

First copy the contract in folder smartcontract from [101 Near] https://github.com/dacadeorg/near-marketplace-dapp/tree/master/smartcontract and run yarn to install

Create the file as-pect.config.js to export module as-pec and add the following code:

module.exports = require('near-sdk-as/imports')

Inside folder assembly create a folder tests. Go to tests create 2 file

• as-pect.d.ts: This file is used to define types that used in as-pect and add the following code

/// <reference types="@as-pect/assembly/types/as-pect" />

• marketplace.spec.ts: This file create an entry for unit test

The project structure should look like this:

├── asconfig.json
├── assembly
|   |──__tests__
│   |           ├── as-pect.d.ts
│   |           ├── marketplace.spec.ts
│   ├── as_types.d.ts
│   ├── index.ts
│   └── tsconfig.json
├── package.json
└── as-pect-config.js

Write a couple of tests for the contract

Navigate to file marketplace.spec.ts assembly/__tests__/marketplace.spec.ts

1. Import all function & model

import { buyProduct, setProduct, getProduct, getProducts } from '../index';
import { productsStorage } from '../model';

2. Import u128 (to parse price amount) & VMContext (VMContext will help us in mock context when testing, such as attaching a deposit to a message.)

import { u128, VMContext } from 'near-sdk-as';

3. Then copy these code:

describe("Test manipulate product data", () =>{
    beforeEach(() => {
        VMContext.setCurrent_account_id('alice.near');
        VMContext.setSigner_account_id('alice.near');
        VMContext.setAttached_deposit(u128.from("10000000000000000000000"));

        setProduct({"id": "100", "name" : "BBQ", "description": "Its BBQ", 
                    "image": "https://i.imgur.com/yPreV19.png", "location": "Mexico",
                    "price": u128.from('10000000000000000000000'), "owner": "dacade.testnet", "sold": 0});
    });
    it("should add product", () => {
        log("setProduct")
        expect(productsStorage.length).toBe(
            1,
            "should only contain one listed product"
        );
    });

    it("should get product", () => {
        const listProduct = getProducts();

        log("getProducts")
        expect(listProduct[0].name).toBe(
            "BBQ",
            "name should BBQ"
        );

        log("getProduct")
        expect(() => {
            getProduct("100");
          }).not.toThrow();

    })
    it("should buy product", () => {
        log("buyProduct")

        expect(() => {
            buyProduct("100")
        }).not.toThrow();
        const listProduct = getProducts();

        expect(listProduct[0].sold).toBe(
            1,
            "sold should increase to 1"
        );
    });
});

Let check what we got here: describe invoke the test , and check our test case with the correct order or not. We use beforeEach to fund near to account test alice.near and setProduct BBQ in each successive test. Now to run test open your terminal and type

yarn asp

After the test is finished, you will see that the results of the passing tests will look like this:

You can refer my previous project unit test, i've applied in this course.

TLDR

git clone https://github.com/anhfactor/near-101-dacade-unit-test
cd near-101-dacade-unit-test
yarn
yarn asp